HUMAN SPLANCHNIC AND FOREARM VASOCONSTRICTOR RESPONSES TO REDUCTIONS OF RIGHT ATRIAL AND AORTIC PRESSURES
HUMAN SPLANCHNIC AND FOREARM VASOCONSTRICTOR RESPONSES TO REDUCTIONS OF RIGHT ATRIAL AND AORTIC PRESSURES
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DOI：
10.1161/01.res.34.4.515
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发表时间：
1974-01-01
影响因子：
20.1
通讯作者：
EISMAN, MM
中科院分区：
文献类型：
--
作者：
JOHNSON, JM;ROWELL, LB;EISMAN, MM
在9名男性中研究了右心房压力和主动脉压力逐渐降低时的局部血管反应。在每项研究中，以-1 mm Hg/min的斜率施加下体负压40 - 50分钟。在对照至-20 mm Hg范围内，右心房压（4项研究）从4.2 mm Hg降至-0.6 mm Hg;心率略微降低（2次/min），主动脉平均压和脉压（6项研究）不变。主动脉压的最大上升速率没有显示出一致的趋势。前臂血流量（30项研究）随着下体负压的出现而下降，并在-20 mm Hg时达到对照值的67%。内脏血流量（14项研究）显著降低了-7 mm Hg，并下降至对照组的89%（-20 mm Hg）。在-20至-50 mm Hg范围内，右心房压力继续下降。4名受试者的主动脉平均压略有下降或保持不变，2名受试者的主动脉平均压急剧下降至-35 mmHg。主动脉脉压在约-20 mm Hg时开始下降，此后线性下降。心率与主动脉脉压的相关系数为-0.86~-0.93。在-50 mm Hg下，前臂血流量下降至对照的55%，内脏血流量下降至对照的65%。因此，发生了显著的血管收缩，而动脉血压没有可测量的变化。我们的结论是，低压压力感受器，大概在心肺区域，启动内脏和前臂血管收缩与更明显的血管收缩发生在前臂。
Regional vascular responses to gradual reductions in right atrial pressure and aortic pressure were investigated in nine men. In each study, lower body negative pressure was applied in a ramp of -1 mm Hg/min for 40-50 minutes. During the range from control to -20 mm Hg, right atrial pressure (4 studies) fell from 4.2 mm Hg to -0.6 mm Hg; heart rate was slightly reduced (2 beats/min), and aortic mean pressure and pulse pressure (6 studies) were unchanged. The maximal rate of rise of aortic pressure showed no consistent trends. Forearm blood flow (30 studies) fell with the onset of lower body negative pressure and reached 67% of the control value by -20 mm Hg. Splanchnic blood flow (14 studies) was significantly reduced by -7 mm Hg and fell to 89% of control by -20 mm Hg. During the range from -20 to -50 mm Hg, right atrial pressure continued to fall. Aortic mean pressure fell slightly or was unchanged in four subjects and fell dramatically at -35 mm Hg in two subjects. Aortic pulse pressure began to fall at about -20 mm Hg and fell linearly thereafter. Heart rate paralleled aortic pulse pressure (r= -0.86 to -0.93). Forearm blood flow fell to 55% and splanchnic blood flow fell to 65% of control at -50 mm Hg. Thus, significant vasoconstriction occurred without measurable change in arterial blood pressure. We concluded that low-pressure baroreceptors, presumably in the cardiopulmonary region, initiate splanchnic and forearm vasoconstriction with more pronounced vasoconstriction occurring in the forearm.